
Glass ^ 

Book / 5 T3 



nu. 



Concerning Wheat and its Mill Products 



. BY . . 



G. L. TELLER. 



/ 



PRODUCTS OF CERTAIN SMALL. MILLS. 



With the adoption of roller milling machinery into flour mills the pro-: 
cesses of flour manufacture and the products themselves have undergone " 
a radical change from what existed under the old system of mill-stone 
milling. A more complete separation of the bran from the flour material 
is made, and the germ or portion of the kernal which produces the sprout, 
finds its way not into the flour as before, but into the offal. In nearly all 
mills the flour is divided into two or more qualities and in many mills the 
offal is divided into two products which are of very different nature and 
which consequently have different food values. 

While among flouring mills, each differs from nearly every other in 
details of construction and arrangement ; they are all essentially the same in 
that the bran is separated from the interior of the grain, and this interior 
is reduced to flour by repeated crushing between rollers followed and inter- 
mingled with numerous separations by suitably arranged bolting machines 
of various kinds. The details of this process must be left to the miller. 
The farmer has to do only with the material which he takes to the mill and 
the products which he takes away or which are sent to him in those sec- 
tions where wheat is not grown. All of these products in considerable 
quantities find their way into various parts of this State. They differ in 
price and have different merits for various purposes. 

With the above points in mind and also for the purpose of learning 
something more definite concerning the chemical nature of different parts 
of 'the wheat grain, which are separated with some distinctness in flour 
milling, a series of investigations has been in progress during the last three 
or more years. They have given some results and promise more in the 
future. 

Among other things undertaken, three separate test runs of wheat 
have been made at two different mills. The parts of the mill in use were 
cleaned as thoroughly as possible of material which it contained from pre- 
vious work, and a like cleaning was made at the end of each run. The 



62 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

wheat used and the resulting products were accurately weighed. Small 
samples of each were taken and submitted to the usual methods of food 
analysis. Complete ash analyses were made of the wheat and pro- 
ducts of the third test run. An attempt was also made to separate the 
products containing nitrogen (crude protein) into different classes based 
upon an extensive study of this subject recently made by Dr. Osborne 
at the Connecticut State Experiment Station. The germ of the wheat 
has in some instances been collected, carefully separated from all foreign 
matter and submitted to partial analysis. The first milling trial was made 
in a long process roller mill (7 breaks) grinding about 40 bushels per 
hour. The other two trials were made in a four break mill, grinding about 
seven bushels per hour and using the plansifter method of bolting. De- 
tailed results of these trial runs and results of some of the analyses made 
are given below. 

In all of these trials winter wheat grown in Washington County, Ark., 
was used. In the first trial was a mixture of several small lots brought in 
during the day by farmers. In the third trial a uniform lot of Fulcaster 
wheat of fair quality, slightly affected with weavil, was used. That used in 
the second trial was a red wheat, variety not known. 

WHEAT MILLING TRIAL No. 1. -MADE JANUARY 2. 1894. 

Weight uncleaned wheat, 7,000 pounds. 

Products. Weight Per Cent of 

Pounds. Uncleaned Wheat. 

Patent Flour 848 12. 11 

Straight Flour 3.964 5 6 - 6 3 

Low Grade Flour 250 3.55 

Bran i> 6 3° 2 3-37 

Tail of Mill (ship stuff) 174 2 -4% 

6,872 98.14 



1.1 



Screenings 7° 

Loss (dust, etc.) 5° -7 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



63 



TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL No. 1 

Figures show pounds of food material in each 100 pounds of product. 





Patent 

Flour. 


Straight 
Flour. 


Low 
Grade 
Flour. 


Ship 
Stuff. 


Bran. 


Whole 
Wheat. 


Pure 
Germ. 


Water 


13-75 

■33 

•17 

1.05 

9.69 

75- 01 
100.00 


I39O 

•47 
.26 

i- 2 5 

10.37 

73-75 

100.00 


13.22 
.90 

•74 

1.70 

12.88 

70.56 

100.00 


12.25 
3.I2 

3-55 

4.80 

16.36 

5902 

100.00 


12.85 
5.80 
6.I4 
5.20 

I5-56 

54 45 
IOO.OO 


13.90 
2.I5 
2.I7 
2.15 

12.31 

63-32 
IOO.OO 


6 80 


Ash 


4.65 


Crude Fiber 


Fat 


14 38 
36.OO 

36.55 
IOO.OO 


Crude Proteids* 

Carbohydrates 


Total Nitrogen 


1.70 

1.65 
05 


1.82 

1.72 

.10 


2.26 
2.20 

.06 


2.87 

2.68 

.19 


2-73 

2.51 

.22 


2.l6 

I.98 

.18 


6-34 













*Crude proteids in these analyses represent the nitrogen found, multiplied by 5.70, this factor being the 
result of the average amount of nitrogen found in the proteids of the wheat kernal hy Dr. Osborne as given 
in the report of the Connecticut Agricultural Experiment Station for 1893, pp. 177-179. For wheat grain this 
factor gives a far more accurate result than does the factor 6.25, which has heretofore been in general use. 



WHEAT MILLING TRIAL NO. 2— MADE MARCH 15. 1894. 

Weight uncleaned wheat, 3,000 pounds. 

Products. Weight Per Cent of 

Pounds. Uncleaned Wheat. 

Patent Flour 529.5 1 7.65 

Straight Flour 1,510.5 5°-35 

Low Grade Flour 69 5 2.32 

Shorts 33° I -io 

Dust Room Contents 24.5 .82 

Bran 723 o 24.10 

Screenings 81.0 2.70 

Sample Cleaned Wheat 1.5 .05 

Loss 27.5 .91 

3,000.0 100.00 



64 



ARKANSAS AGRICULTURAL EXPERIMENT STATION. 



TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL NO. 2. 

Figures show pounds of food material in each ioo pounds of product. 





Patent 
Flour. 


Straight 
Flour. 


Low 
Grade. 


Dust 
Room. 


Ship 
Stuff. 


Bran. 


Wheat 
Cleaned. 


Water 


I4.05 

.26 
•17 

•93 

8.49 

76.10 

100.00 


I4.O4 

•35 

.22 

1.27 

9.80 

74-32 
100.00 


I3.9O 

•78 

•54 
1.80 

13- 79 

69.19 

100.00 


I3.04 
2.8l 
6.06 

3 15 

12.65 

62.29 

100.00 


13 5° 
I 21 

•98 

2.5O 

I4.82 

66.99 

IOO OO 


12-55 
5-8 5 
6.51 
4.80 

16.30 

53-99 
100.00 


13 70 

I.85 

2.03 

I.85 

II.40 

69.17 

lOO.OO 


Ash 

Crude Fiber 

Fat 

Crude Proteids* 




Total Nitrogen 


1.49 


1.72 


2.42 


2.22 


2.60 


2.86 


2.00 



Weight uncleaned wheat, 
Products. 



* Crude proteids equal nitrogen multiplied by 5.70. See under Milling Trial No. 1. 

WHEAT MILLING TRIAL No. 3.— MADE NOVEMBER 30, 1894. 

,000 pounds. 

Weight 
Pounds. 

Patent Flour 774 

Straight Flour 1,260 

Low Grade Flour 116 

Dust Room Contents 35 

Ship Stuff 34 

Bran 714 



Screenings. 

Tailings 

Loss 



2,933 

55 



Per Cent of 
Uncleaned Wheat. 
25.80 
42 00 

3-87 
1. 17 

23.80 

97-77 
1.83 

■33 

.07 



TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL No. 3. 

Figures show pounds of food material in each 100 pounds of products. 





Patent 
Flour. 


Straight 
Flour. 


Low 

Grade. 


Dust 
Room. 


Water 


I4.OO 

•31 
.18 

.85 
8.78 

75-88 
IOO 00 


13.98 
.40 
.26 

1.00 

9.98 

74-88 

lOO.OO 


13.90 
.70 
•47 

i-75 

12.14 

71.04 

100.00 


I3-05 
2 50 

4.4I 

3-65 

12-37 

64.O2 

lOO.OO 


Ash 

Crude Fiber 

Fat 

Crude Proteids* 








Total Nitrogen 


i-54 


i-75 


2.13 


2.17 



Ship 




Stuff. 


Bran. 


12.50 


I2.6o 


3.08 


5- 2 5 


3-07 


6.5I 


4-75 


5.OO 


15^5 


I5-56 


60.75 


55- 10 


100.00 


100.00 


2.78 


2-73 



13.80 

1.62 

2.50 

1.90 

II. 17 

69.11 

100.00 



1.96 



*Crude Proteids represent the nitrogen multiplied by 5.70 as indicated in note under results of Milling 
Trial No. 1. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



65 



The dust room contents mentioned above consists largely of fhe outer 
portion of the bran mixed with a little material which would otherwise 
have made flour. A sample of this material was sifted to remove the 
flour particles and the residue, consisting of the material which millers call 
4i bees wings" was analyzed. The results are given below in connection 
with the analysis of screenings from milling No. 3. 



TABLE SHOWING COMPOSITION OF SCREENINGS AND SIFTED DUST. 





Water. 


Ash. 


Crude Fiber. 


Fat. 


Crude Pro- 
teids. 


Carbohy- 
drates. 


Sifted Dust 6.25 

Screenings 12.70 


2.25 
2-57 


19.77 

3-55 


.78 
2.5O 


S-i3 

12.03 


65.82 
66.65 



The analysis shows this wheat screenings to be a valuable article of 
food for stock and such is the usual case with this offal. A short discus- 
sion of the food value of ship stuff and bran is given in Bulletin No. 30 of 
this station, page 158, and is in accordance with what the above analyses 
teach. As that bulletin is probably in the hands of most of the readers of 
this one, the discussion need not be repeated here. In the smaller mills 
these articles are usually run together and sold simply as bran, but they are 
kept separate in larger mills, and that which is sold as ship stuff will usu- 
ally cost about $i. 00 per ton more than the bran. The relative compo- 
sition of these two articles differs in the output of different mills, but in 
general the ship stuff has an increased food value corresponding in a meas- 
ure with the increase in price. 

CLASSIFICATION OF FLOURS. 

Since the details of flour manufacture differ so greatly in different 
mills it is apparent that the products from all mills will not be of uniform 
quality. So, too, the wheat used, its condition when milled, the condi- 
tion of the mill and other things tend to vary the quality of the output 
from the same mill at different times. These variations are often recog- 
nized by purchasers of the flour, and on the other hand, flour is probably 
often blamed for being poor when the difficulty lies wholly or in part with 
the user of it, as when it is not adapted to the special details of bread 
baking habitually practiced by that person. 

Nearly all mills sell their flour under special brands or trade names. 
Often these are registered under government laws and can be used by 
other millers only at their peril. Each miller will have as many of these 



66 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

trade names as he has qualities of flour. If the flour sold under the same 
name were always of uniform quality, purchasers might be guided mate- 
rially by them, but for reasons indicated above, these qualities are not 
always uniform. There is little doubt, however, that the mill brand fur- 
nishes the most reliable guide which purchasers of small quantities of flour 
have for judging of the quality of the article which they wish to purchase. 

There are means at the disposal of large consumers of flour which 
enable them to judge quite accurately of the quality of the article they are 
buying. Such means are, comparison of color, capacity to take up water, 
accurately conducted baking tests which may be readily applied to small 
quantities of many samples of flour, and other means, the details of which 
cannot be given here. These methods are resorted to by professional 
bakers and others, the amounts of whose purchase justify the expenditure 
of the time and labor and the purchase of the necessary apparatus. 

In large market centers, such as St. Louis, Chicago and Philadelphia, 
the flour which is bought or sold by local dealers is often submitted before 
the transfer to inspection by authorized flour inspectors. These report 
upon the average weight and condition of the separate packages and their 
contents, and the terms of the sale are arranged accordingly. 

A quite thoroughly organized inspection is carried on in St. Louis 
under the direction of the Merchants' Exchange. Here, when inspected, 
the packages of flour are stamped with the brand of the flour inspector, 
which mark indicates the date of inspection, the weight of the package, 
the condition of the contents as to soundness or unsoundness, and may in- 
dicate its quality or grade. Quality or grade are indicated by names 
adopted by the Board of Flour Inspectors in much the same way as trade 
names are adopted by a mill owner. The names of the grades of the St. 
Louis Merchants' Exchange Board of Flour Inspectors are : Patent, Extra 
Fancy, Fancy, Choice, Family. The first named indicates the whitest and 
highest quality, the last indicates the darkest and lowest grade of flour. 
The other names indicate intermediate grades corresponding to the posi- 
tions which the names occupy in the above list. 

As a guide for the use of the various deputy flour inspectors the Board 
of Flour Inspectors prepares a series of standard grades to be used for 
comparing with the flour which is being inspected. Many of the millers 
of St. Louis and vicinity also obtain samples of these standards and gauge 
the qualities which they produce by them. To provide against changes 
which flour undergoes with age, fresh standards are prepared at intervals 
of two or three months. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 67 

Market quotations from St. Louis, Memphis and Little Rock state 
prices for all or part of the above grades of flour and use those terms for 
designating the different qualities of flour upon the market. Other cities, 
like Philadelphia, Baltimore and Boston, use different names for their 
standard grades, and some cities in which inspection is carried on use none 
whatever. 

Flour inspection in the various cities is for the most part under the 
control of merchants who have organized and established the system for 
their mutual protection. There is every reason for believing that it is a 
most effectual means of protecting both buyer and seller. More than a 
suggestion as to the value of an efficient system of flour inspection, where- 
by the actual quality of any flour in the market may be known to the con- 
sumer, or purchaser of small quantities, cannot be given here. There are 
reasons for believing that such a system would be of material benefit to all 
who have anything whatever to do with this article. 

COMPOSITION OF FLOURS. 

An examination of preceding tables of analyses show that the highest 
proportion of carbohydrates is found in the whiter flours. In a perfectly 
ripened, unsprouted wheat these carbohydrates consist almost entirely of 
starch. The low grade flours contain much less carbohydrates than the 
patent flours. The analyses also show an increase of fat, ash and fiber in 
the lower grades of flour. A very marked variation in the amount of crude 
proteids also occurs. Further examinations, the results of which are not 
given in the preceding tables, show the different groups of proteids, which 
together make the total proteids to differ very markedly in their relative 
proportions in these different grades. 

The proteids which are considered of most importance in wheat flours 
are those which constitute what is known as gluten. Gluten is an elastic 
semitransparent mass of material which remains when flour is carefully 
washed with water in such a way as to remove the large quantities of starch 
and other matters which always occur with it. If a few spoonfuls of flour 
are mixed with water to a moderately stiff dough and allowed to stand for 
an hour in a saucer or other convenient dish the threads of gluten may be 
readily seen by pulling the mass apart with the fingers. If the mass of 
dough be placed in a strong cotton or linen cloth and worked between the 
thumb and fingers in a quantity of water until a fresh supply of water does 
not become milky from separated starch after a few minutes working, nearly 
pure gluten will remain in the cloth and its nature can then be readily seen. 



68 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

It is this gluten which gives wheat flour its peculiar value for bread 
making purposes. The carbonic acid gas which is formed by the growth 
of yeast in a mass of bread dough, or which is set free from baking powder 
when it is wet with water, or from baking soda when it is wet with sour 
milk, accumulates itself in numerous small pockets which it forms in the 
dough. These pockets are formed because of the presence of this tenacious 
gluten which is so elastic as to permit the gas to force it aside without 
breaking it and yet so compact as to prevent the escape of the gas. The 
walls of the pockets formed retain their places when the bread or cake is 
baked, giving a light porous loaf very different from that of bread made 
from corn flour. Corn contains no gluten. 

The gluten of different flours differs not only in amount but in quality. 
Bakers like a flour containing much of a very strong gluten. Such flours 
will take large quantities of water and make more bread to a given weight 
of flour. Consumers of baker's bread and those who bake their own flours 
do not want water from this source. They want bread. However, most 
all who use light bread wish a light porous loaf, and to obtain this a flour 
must be used which contains a sufficient amount of a good quality of gluten. 
They also want a bread which will retain moisture well, which will be light 
in color and which will be agreeable* to the taste. These qualities they 
cannot get by the use of a very low grade of flour. In many instances they 
probably cannot get all of them by the use of a very high grade, because 
such flours are made from the more starchy portion of the grain and are 
deficient in gluten. 

Flour from hard spring wheat contains much gluten of a high quality 
-and is much sought after by some bakers, who use it either alone or to mix 
with other flours. There does not seem to be reasons for believing that 
flours from soft winter wheat produced in this section of country are so 
•deficient in gluten as to make them in any way inferior for general use. 
This is especially true since much of the bread consumed in this State is 
•used in the form of warm biscuit, for the making of which flours from soft 
wheat are even more suitable than from hard wheat. Lower grades of flour 
can also be used for the making of warm bread than for the making of the 
so-called light bread. The most suitable use for human food to which very 
low grades of flour can be put is to the making of griddle cakes for which 
purpose they seem even superior to the better qualities of flour. 

It is a common opinion of many that the highest priced article of any 
kind will prove most economical in the long run. This is not necessarily 
true of wheat flours. High priced flours are preferable to some because of 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 69 

their very white color. The medium grades of flour will contain more 
gluten and yet do not partake in a very large degree of those objectionable 
qualities found in a very low grade. Different individuals differ in their 
tastes and some will prefer the flavor of a lower grade to that of the highest. 
There is unquestionably a difference in the amount of waste which will 
occur from breads made of different qualities of flour, and this difference will 
vary for the same flour according to the tastes of consumers of the bread. 
In general the lower grades of flour from the same wheat will contain 
the highest proportion of gluten. This increase of gluten is, however, 
less than the increase of crude proteids. There has been a common prac- 
tice of pronouncing food containing a large proportion of proteids to be 
superior foods ; that is, foods supplying a greater amount of nutriment. In 
the case at least of different flours from the same wheat there are other 
matters which come in direct opposition to this. As bearing directly on 
this point the following extract is quoted from a valuable paper on the 
chemistry of wheat and flour published by Lawes & Gilbert, of England, 
in 1857: 

"It is also well known that the poorer classes almost invariably prefer the whiter 
bread ; and among some of them who work the hardest, and who consequently would 
soonest appreciate a difference in nutritive quality (navvies, for example), it is distinctly 
stated, that their preference for the whiter bread is founded on the fact, that the browner 
passes through them too rapidly; consequently, before their systems have extracted from 
it as much nutritious matter as it ought to yield them." 

The authors of this sentence attribute the facts stated to the mechani- 
cal action of the hard, branny particles upon the intestines. In those days 
milling was entirely done by the use of millstones, and a much larger pro- 
portion of bran found its way into the flours than occurs with the roller 
process now in use. An examination of the tables of analyses does not 
show a large proportion of crude fiber even in the lowest grades of flour 
and yet there are some reasons for believing that this laxative influence 
possessed by low grade flours in those days still occurs. The proteids not 
gluten are much more abundant in the bran than in the flours, and the laxa- 
tive effect of bran-mash fed to horses and other animals which consume such 
coarse fodders as hay, can hardly be attributed to the hard, branny particles, 
because bran contains not more than one-fifth as much crude fiber as the 
average hay, and that which it does contain is not less easily softened by 
moistening than that which is contained in the hay. It would seem, there- 
fore, that the laxative effect of bran and low grade flours is due rather to the 
kind of proteids which they contain than to the mechanical action of 
their branny particles. 



70 



ARKANSAS AGRICULTURAL EXPERIMENT STATION. 



This laxative action of bran and low grade flours may be made to 
serve a useful purpose as a food for some, and finely ground whole wheat 
meal, or graham flour, may be especially useful for that purpose and for 
giving a change of food as well as for supplying a larger proportion of bone 
forming material, which it contains as ash. Where bread forms a very 
large proportion of the food this special value of the ash constituents, 
especially for growing children, may be great. Where considerable quan- 
tities of other foods, such as vegetables, milk and meat, are consumed, the 
bone material will be supplied in sufficient quantities even when the very 
whitest qualities of flour are used. Among other foods, peas, beans and 
oatmeal are especially rich in bone forming material. 

THE FERTILIZER ELEMENTS CONTAINED IN WHEAT. 

The ash of wheat is made up chiefly of the phosphates of potash, 
magnesia and lime. The results of a complete series of analyses of the ash 
of the products obtained in the third milling trial is given in Part 2 of this 
Bulletin, and the percentage of all the ash ingredients of each ash is there 
shown. For the purpose of illustrating here some important points, the 
absolute weight, in pounds, of the phosphoric acid, potash, magnesia and 
lime computed for the entire weight obtained of each of the mill products, 
and of a corresponding amount of the cleaned wheat, are given in the table 
below. The weight of total nitrogen occurring in each is also given. 

TABLE SHOWING WEIGHT OF CHIEF ASH CONSTITUENTS OF WHEAT AND ITS 

PRODUCTS. 





Patent 
Flour, 
lbs. 




774- 

2-399 

I-I53 
•924 
.105 

•139 
II.92 




Phosphoric Acid 

Potash 

Magnesia 







Straight 
Flour. 


Low 
Grade. 


Dust 
Room. 


Ship 
Stuff. 


Bran. 


Wheat. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


I26o. 


Il6. 


35- 


34- 


714. 


2933- 


5.040 


.812 


•875 


I.O44 


37342 


47-5H 


2.486 

I.830 

.322 

.287 


■431 
.262 
.076 
■037 


•437 
.270 

•i>3 
.031 


■570 
•293 
.138 
.029 


19.720 

IO.527 

5-512 

■933 


24 715 

14 112 
6.286 

1-473 


2205 


2.47 


.76 


•945 


19.50 


57-48 



It will be seen from the above that of the valuable fertilizing elements 
which occur in wheat there are found in those mill products which are used 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 71 

for stock food, about seven-eighths of the entire phosphoric acid, eleven- 
fourteenths of the potash and three-eighths of the total, nitrogon. The total 
value of these three fertilizing elements, based upon prices at which they 
can be obtained in market centers of this State, is $7.50 for the 50 bushels 
of wheat. Almost one-half of this value of fertilizing elements is found in 
the bran and other offal. As has been pointed out in previous bulletins of 
this division of the Experiment Station, little of these fertilizing elements 
are retained by the animal to which the food is fed. If the bran be recov- 
ered from the mill to which the wheat is taken, fed to stock and the result- 
ing manure carefully saved, nearly one-half of the soil fertility which would 
otherwise be lost in the selling of the wheat will be preserved and the live- 
stock will have the benefit of a most excellent concentrated food. Readers 
are here reminded, however, that this is only one argument concerning a 
method of practice, a discussion of which does not come under the scope 
of this publication. 

It may be further pointed out in this connection that Lawes and Gilbert 
in England, have found as partial results of an extensive experiment on 
wheat, grown under different methods of manuring and for many years in 
succession on the same soil, that the average amount of straw which will 
produce 50 bushels of wheat is about 5,000 pounds. They found further 
that this straw will contain an average of 7.6 pounds of phosphoric acid, 
21.5 pounds of nitrogen, and 44.8 pounds of potash. These, valued at the 
same prices as in the preceding paragraph, would show the fertilizing 
elements in the straw to be worth $4.53, or about three-fifths of the value 
of tbe fertilizing elements in the 50 bushels of wheat which the straw would 
produce. The straw itself contains fertilizing elements greater in value than 
are those contained in the flour of the wheat. 

One of the greatest needs of many of the soils of this State is more 
vegetable matter, and straw applied to the soil has a value beyond that due 
to the presence of the most important fertilizing elements which it contains. 
In those sections where wheat is produced the straw should be preserved 
and made to assist in maintaining the fertility of the soil. 

The finding of zinc in the ash of this wheat may be mentioned as a 
point of special interest. The amount found would equal about 1 pound 
of pure zinc to each 500 bushels of wheat. So far as it has been possible 
to learn, this small amount of zinc has no special influence upon the growth 
of the plant nor is it in any way injurious to animals or human beings eating 
the grain. It is found most abundantly in the ash of the outer portions of 
the grain and is present in the flour ash in much less quantities than in the 



72 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

ash of the bran. In the ripened wheat it seems to have been transferred 
almost completely from the straw to the grain. Zinc was also found in oats, 
clover hay and corn cut before tasseling. All of these were produced upon 
soil in the vicinity of that producing the wheat which was used in the mill- 
ing trial. An examination of the first 6 inches of this soil showed it to 
contain about i pound of zinc to each 1,000 pounds of earth. Zinc has 
been previously found in the ash of many plants and of some animals in 
Europe. Its presence in considerable quantities in drinking water has 
produced no noticeable injury to those using it for many years. 

LOSS DURING THE SPROUTING OF WHEAT. 

While everybody recognizes that wheat is injured by sprouting, as when 
in shock, the amount of loss which occurs is not generally understood. 
In an experiment for a purpose pointed out in Part 2 of this Bulletin, equal 
weights of the same wheat were sprouted, under uniform and most favor- 
able conditions, for different lengths of time varying by intervals of twenty- 
four hours each. Each sample at the close of its sprouting period was 
carefully air dried and later the absolute amounts of dry matter in each 
and in the original wheat were determined. This was necessary to give a 
uniform basis of computation, as otherwise accidental variations in the 
amount of moisture may have given misleading results. In the following 
table is given the amount of wheat which would remain from 100 bushels 
of the original wheat after it had sprouted for the number of hours shown 
in the first column of the table and had then been dried till it contained 
the same amount of moisture which was present before it was wetted for 
the sprouting. The number of bushels lost from each 100 bushels of the 
original wheat is also indicated. 

TABLE SHOWING LOSS OF WEIGHT UNDERGONE BY WHEAT SPROUTING FOR 
DIFFERENT LENGTHS OF TIME. 

„,. „ ., Part? Remaining of Parts Lost of 

Time Sprouted. Each 1QQ Parts> Each 1QQ p arts> 

24 hours 98 5 1.5 

48 hours 97.5 2.5 

72 hours 94.1 5-9 

99 hours 93-3 6.7 

120 hours 89.9 10. 1 

144 hours 88.2 11.8 

At the end of the sixth sprouting period two of the more advanced 
grains were beginning to burst their first leaf and a large number of other 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 73 

grains were not far behind in the sprouting stage. The most advanced 
kernals were, however, not beyond the stage where wheat shocks begin to 
turn green from the sprouting grain. It was endeavored to carry on this 
experiment under such conditions that the entire amount of wheat was 
given the best possible conditions for its sprouting. It is probable that the 
sprouting of the entire mass of wheat in shock does not generally occur, 
but it is apparent from the foregoing results that there is a decided loss in 
the weight of the harvest when wheat is allowed to sprout for a very short 
time only, and the amount of loss for a given length of time will be 
dependent upon the amount of wheat affected. 

Aside from the loss in weight which occurs in the sprouting of wheat, 
marked chemical changes are brought about which decrease greatly the 
value of the article for bread baking purposes, and probably also as a food 
for stock. 

The importance of protecting the wheat by proper stacking or storing 
in barns as soon as possible after it is ripe and dry is great. The expense 
of stacking will often be small as compared with losses which may occur 
by attempting to wait till a machine can be procured for the purpose of 
threshing direct from the shock. 

It is possible that the lack of profit to the farmer is often brought 
about through the many small losses of this character which might be pre- 
vented. Successful manufacturers, merchants and others make it a point 
to look after the apparently unimportant details of their business with the 
greatest of care and to insure against loss, whether by fire, wind or rain, 
is almost universally acknowledged to be a sound business principle. 

G. L. Teller, 

Station Chemist. 



Part 2 of this Bulletin contains a record of certain investigations con- 
cerning wheat and its mill products, the results of which have either been 
briefly stated for the use of the farmer in Part i, or are not yet sufficiently 
developed to be adapted to their needs. These investigations are, how- 
ever, of more or less importance to experiment station workers and others 
engaged in scientific studies, and that they may be accessible to such they 
are grouped together and published in a limited edition of a few hundred 
copies only. Parties desiring a copy of the same may obtain it by writing 
for Bulletin No. 42, Part 2. 

Part 2 of this Bulletin treats of the following subjects : 

A Complete Ash Analysis of Wheat and its Mill Products. 

Alumina a Constituent of the Ash of Certain Wheat. 

Zinc a Constituent of the Ash of Some Arkansas Farm Plants. 

Studies Concerning the Proteids of Wheat and a Method for their 
Quantitative Separation. 



COMPOSITION OF THE ASH OF A WHEAT AND 
ITS MILL, PRODUCTS. 

The following series* of ash analyses was made for the purpose of 
obtaining some further information concerning the distribution of various 
ash ingredients in the wheat grain and in the different products of modern 
flouring mills. The samples examined are those of the milling trial No. 
3, of which detailed results are given in Part i of this bulletin. The 
figures given in the table indicate in per cent of total ash, the amount of 
each constituent named. 





Patent 
Flour. 


Straight 
Flour. 


Low 
Grade. 


Dust 
Room. 


Ship 
Stuff. 


Bran. 


Wheat. 




2-33 

.41 

•47 

38.50 

0.00 

5-59 

4-39 

48.05 

.16 


1.28 

•15 
.26 

36.31 
O.OO 
5.65 
6.44 

49-32 
•52 

.04 
99-97 


•5° 
.12 

• 2 5 

32.27 

0.00 

4-5i 

9-33 

.00 


1-34 
.04 

•30 

30.85 

0.00 

3-53 
12.90 

49-94 
•58 


.49 
.18 

•37 

28.03 

O.OO 

2.8o 

13-27 

54.62 

.00 


•97 

.07 

.27 

28.19 

0.00 

2.50 

14.76 

52.81 

.10 

.01 

.27 

99-95 


1,04 
.1 1 






.27 

29.70 

O.OO 








^?.IO 


Magnesia 


I3-23 

52.14 

.22 


Phosphoric acid 




•OI 


Zinc oxid 




-46 


•36 


.24 






100.08 


Sum 


99.90 


99.94 


IOO.I2 


IOO.06 






Per cent total ash in each 


•3i 


.40 


.70 


2.50 


3.08 


5- 2 5 


1.62 



The ashes for these analyses were prepared in a Fletcher's muffle 
furnace No. 5, heated by an ordinary Fletcher's gas cooking burner. The 



*The results of a somewhat similar series of ash analyses by Dempwolf are given in Annalen der 
Chemie und Pharmacie, Bd. 149, pp. 343, 350. 1869. 



76 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

platinum dishes in which the material was burned are capable of holding 
about fifty grams of the pulverized material each. The muffle is just large 
enough for two of these dishes. As the material in the dishes decreased 
sufficiently in bulk 25 grams of fresh material was added and this was 
continued till enough had been taken to produce a sufficient amount of ash. 
The burning was then continued till the ash was of a very light gray color. 
Care was taken in each instance that the temperature of the muffle in its 
hottest place should not rise above a gentle redness. The dishes were 
protected from the bottom of the muffle by a thick sheet of asbestos cloth. 
The ash thus produced did not fuse and was perfectly loose and free. The 
small amount of unburned carbon was determined and deducted from the 
crude ash to give the pure ash upon which all computations are based. No 
carbonic acid was found. The analyses of ash were all made by me per- 
sonally with as much care as could be commanded. 

It has been suggested that the absence of sodium and chlorine in these 
ashes may be due to their having been volatilized during the burning. This 
error is possible. However, it could not well be prevented. Attempts 
were made to extract the charred mass with dilute acetic acid as soon as 
all volatile matter was driven off but the char was a porous, very hard mass, 
which could be pulverized only with great difficulty and which could not 
be well extracted otherwise, so that the probabilities of error by this method 
seemed much greater than by direct burning. The method is, too, essen- 
tially that used by Lawes & Gilbert in the preparing of the considerable 
number of wheat ashes which they have had analyzed, except that they 
were not required to add the unburned material in parts. 

Among the variations in composition in the ash from different parts of 
the wheat grain the most noticeable are the very marked increase in the 
proportion of potash and lime toward the interior of the grain and the still 
greater decrease in the proportion of magnesia in the same direction, that 
is, from the bran to the whitest flour. The presence of zinc will be dis- 
cussed later. It was present only in very minute quantities in the ash of 
the flour. The amounts could not be determined in the patent and low 
grade flours for the want of more material. 

The variation in the amount of sulphuric anhydrid present was to be 
expected. It indicates nothing special. Any sulphates present may easily 
have been reduced and the sulphur volatilized in the burning of the ash. 
Sulphur is alwa)s present as one of the essential elements of the proteids, 
and would, under suitable conditions, have been converted into sulphates 
during the burning. The presence or absence of sulphur in the ash is 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



77 



probably largely dependent upon the relative proportion of the strong bases 
and the phosphoric acid in the material burned. A determination of the 
total sulphur in each material was made by fusing 2 grams of the substance 
with a sufficient amount of nitrate of potash and potassium hydrate in which 
the absence of sulphur in weighable quantities had been verified. 

PER CENT OF SULPHUR IN WHEAT AND ITS MILL PRODUCTS. 



Patent 
Flour. 


Straight 
Flour. 


Low 
Grade 
Flour. 


Dust 

Room 

Contents. 


Ship Stuff. 


Bran. 


Wheat. 


.09 


.IO 


.16 


•15 


•17 


.21 


•13 



ALUMINA IN THE ASH OF WHEAT. 

The finding of alumina in the ash of plants has been often mentioned 
but it has been attributed to possible clay or dust adhering to the surface 
of the material from which the ash was obtained. Wanklyn* and Cooper 
report alumina to be a usual constituent of wheat flours. They attribute 
the presence of a pirt of it to the wearing down of the millstones. This 
could not have been a source of the material in these mill products, as the 
wheat was crushed entirely by iron rollers and an examination of the 
amounts of alumina found in the mill products and in the whole grain in- 
dicate that it is no more foreign to the true ash than any of the other con- 
stituents named. To bring further proof on this point, 100 grams of the 
unground wheat was carefully washed with distilled water, and after drying, 
was burned without being pulverized. The same amounts of both alumina 
and zinc were found as in the wheat which had not been washed. It seems 
a little remarkable that the zinc should have accumulated to the greatest 
extent in the ash of the bran while the alumina and silica should have 
reached their largest proportion in the ash of the finer flours. Alumina is 
found to be of frequent occurrence in the mineral waters of this State. t 

To ascertain as to whether alumina will be present in the ash of wheat 
grown on a very sandy soil, a sample of wheat was obtained through the 
kindness of Dr. Palmer, of Grayling, Mich., where it had grown upon the 
Jack Pine Plains. The wheat was thoroughly washed, pulverized and 
burned and treated for alumina as in the other instances, but none was 
found. 



* Bread analysis, p. 24. 

{Arkansas Geological Survey. Report for 1896, Vol. 1. 



78 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

In all these analyses the phosphates of iron and alumina were sepa- 
rated from the remainder of the ash by the use of acetate of sodium or 
ammonium, acetic acid and the temperature of boiling water. To remove 
other phosphates which were carried down from the concentrated solutions 
they were dissolved in acid and reprecipitated. These phosphates were then 
weighed in a platinum crucible in which the filter on which they were 
collected had been burned. They were then dissolved in the smallest 
possible quantity of hydrochloric acid, and the solution made to ioo c. c. 
10 c. c. of this solution was placed in a Nesslerising cylinder containing 
one cubic centimeter of strong nitric acid. Two cubic centimeters of 
ammonium sulphocyanid of the usual reagent strength was added and the 
contents of the cylinder made to the 50 or 100 c. c. mark. Other Ness- 
lerising tubes were filled in like manner, except that in place of the solu- 
tion to be analyzed different quantities of a solution of ferric chloride con- 
taining .0001 grams of iron to each cubic centimeter were used. By 
carefully comparing tints in the different cylinders, the number of one- 
tenth milligrams of iron in the 10 c. c. of solution compared may be 
readily ascertained.! This has been found to be a very ready and satisfac- 
tory method of estimating the small quantities of iron contained in these 
ashes. The alumina was computed from the aluminum phosphate found 
by difference. The presence of the alumina was also verified by the 
usual qualitative methods. 

OCCURRENCE OF ZINC IN THE ASH OF SOME PLANTS. 

Certain ash elements are found in all plants and are essential to their 
development. Other elements which are only occasionally present in soils 
may be taken up by plants growing on them though they may have no effect 
upon the growth of the plant. Among these are manganese, copper, zinc 
and even arsenic. Their presence is a matter of interest and their general 
distribution seems a question worthy of some attention. Animals and 
human beings using the plants for food may accumulate the metals in their 
system and the discovery of their presence by those unacquainted with 
their frequent occurrence might lead to various complications, such as the 
apparent proof of supposed criminal poisoning when none had really 
occurred. 

The finding of zinc in this wheat was quite unexpected. Though the 
. section of country in which the wheat was grown shows to the most casual 

JBread analysis. Wanklyn and Cooper, p. 34. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 79 

observer, characteristics in common with some regions in Southern Mis- 
souri, where zinc is obtained in abundance, zinc has never been found in 
paying quantities in this vicinity. The history of the wheat was sought out 
and a sample of the first 6 inches of soil in the field in which it was grown 
was obtained. This surface soil is, when dry, of a light mouse color. In 
quality it is a clay loam containing when taken from the field, a few gravel 
stones of considerable size. The deep subsoil is heavy clay of yellow or 
reddish yellow color. The sifted air dry soil yielded to hydrochloric acid 
.42 per cent of zinc oxide, equal to 7.8 pounds of metallic zinc per ton. 

Two samples of wheat grown on opposite sides of this first field were 
taken soon after they were cut in the summer of 1895. The ash of one was 
found to contain .30 per cent of zinc oxide and of the other .12 per cent, 
the latter being only one-half of that found in the ash of the wheat milled. 
Among the mill products of this latter wheat it was found most abundantly 
in the contents of the dust room which is made up largely of the outermost 
coat of the bran. The next greatest quantity was found in the ash of the 
ship stuff and the least in the ash of the flour. No zinc oxide whatever 
was found in the ash of 100 grams of the straw from one of the above 
wheats and none in the ash from 50 grams of the other straw. Red clover 
growing on the field which produced the wheat in 1894 showed .004 g. 
zinc oxide in the 7.449 g. of a very pure ash from 115 g. of the entire 
plant. This corresponds to .06 per cent of zinc oxide in the ash of the 
clover. Corn fodder cut from an adjacent field before tasseling and when 
about 3 feet high, showed .0065 grams of zinc oxide in the 8.670 g. of ash 
from 90 g. of the air dry fodder. This corresponds to .07 per cent of 
zinc oxide in the ash of the corn fodder. This ash was, however, a little 
dark and contained a little carbon, the amount of which was not determined. 
A sample of ripe oats grown on a field not far away contained .12 per cent 
of zinc oxide in the 2.840 g. of a very light gray ash from 100 g. of the 
grain. Here again no zinc was found in the straw. It would seem, there- 
fore, that as the plant ripens the zinc is transferred to the outer portion of 
the grain produced. 

Frequent mention has been made of the presence of zinc in a small 
plant ( Viola calminaria) which grows in the vicinity of zinc mines in 
Europe. It is written 1 that the growth of this plant has been taken as an 
indication of the presence of zinc and that when made to grow upon a soil 
which contains no zinc it undergoes a change of form and color. Lechar- 
tier and Bellamy, 2 of France, investigated the presence of zinc in the ash of 

1. Encyclopedic Chetnique, t. x., p. 97, and Annates Agronontiques, t. x., p. 478. 

2. Comtes Rendus, t. x. LXXXIV. No. 15, p. 687. 



80 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

certain plants, animals, and their products. They found it in notable 
quantities in the livers of two men of different occupations and dying of 
different diseases. They also found it in veal, beef, the eggs of poultry 
and in the grain of wheat, barley, maize, harcot beans and winter vetch. 
They also examined for it the sugar beet, the stems of corn and green clover 
and were not satisfied of the presence of zinc in these. In their determin- 
ation of zinc, as well as in those made here, care was taken that the zinc 
could not come from any other source than the material examined. The 
presence of zinc in considerable quantities in many plants has been verified 
by Sachs and by still others. 

Ant. Beaumann 3 has grown various plants in solutions containing salts 
of zinc and all mineral matters necessary for the development of the plant. 
He found that when the zinc present did not exceed one milligram per 
liter of water, the plants grew very well and that the zinc was absolutely 
inoffensive. When the amount of zinc was increased to about five milli- 
grams per liter it became a poison and the plants soon perished. When 
solutions of either sulphate or carbonate of zinc were so strong as to de- 
stroy plants having their roots in them they had no evil effect when added 
to a soil upon which similar plants were growing. This is attributed to 
the precipitation of the zinc from solution by the presence of certain of 
the soil ingredients, thus rendering it much less capable of entering the 
roots of the plant. This author attributes the injurious action of the zinc 
to its attacking the chlorophyll. He also cites the experiments of M. 
Raulin, in which it was found that the presence of a small quantity of zinc 
had a decided beneficial influence upon the growth of black mould {asper- 
gillus niger). This plant contains no chlorophyll. 

So far as known the presence of zinc in plants exerts no influence 
upon animals consuming them, and it is stated upon the authority of E. 
Mylins 4 that water of a certain public well of Europe which contains .007 
grams of zinc oxide per liter has been used for drinking purposes for more 
than a century without any perceptible injury to man or beast. 

3. Die Landszuirtschaftichen Versuchsstationen, XXX. volume ler. fascicule. Abstract in Annates 
Agronomiques, t. x., p. 478. 

4. Chemical News, vol. XLII, p. 49. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 81 

THE QUANTITATIVE SEPARATION OF WHEAT 

PROTEIDS. 

Extensive investigations have been made and much has been written* 
by various experimenters concerning the presence of amides in plants, 
especially young and immature ones, and concerning the formation of 
amides during the sprouting of seeds and of their later transformation into 
proteids in the growing seedling. Extensive investigations have also been 
made concerning the character and composition of proteids in plants, 
especially in mature grains and seeds, but so far as known no efforts have 
been made to study the relative formation and decomposition of such pro- 
teids which normally take place in seeds during their development and 
germination, nor does any extensive investigation seem to have been made 
concerning the relative proportion of different proteids in like grains or 
seeds of different characteristics such as often occur in plants of the same 
species when grown under different conditions as to soil, climate, seasons, 
etc. While such knowledge concerning the proteids of any agricultural 
plant gives promise of being of ultimate value to the science of agriculture 
it seems likely that a knowledge of the kind indicated concerning the 
proteids of wheat will be of special value because of the probable close 
association of these variations with the milling qualities of the grain and 
the consequent value for baking purposes of the flours produced. It seems 
probable that the relative proportions of the different proteids may bear 
close relations to well recognized characters of the grains. 

The nature and amount of gluten contained in wheat flour frequently 
gives important information concerning the quality of that flour. It also 
gives some information concerning the value of a wheat for flouring pur- 
poses and more or less use has been made of knowledge concerning it in 
selecting varieties of wheat for growing in special localities. The mechan- 
ical methods of separating gluten which are now extensively used are 
acknowledged to be very imperfect and unsatisfactory and it seems that a 
a short but definite chemical method of ascertaining the amount of gluten 
in wheat or flour will be of great value to the chemist in his examination of 
those articles. 

The important work of Osborne and Voorhees in the Connecticut Ex- 
periment Station has given definite information concerning the kinds of 



* For review and bibliography concerning studies on Asparagin up to 1879 see paper by M. Campus 
Annales Agronomiques, t. V. p., 578. 



82 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

proteids in sound mature wheat. Accepting for the most part their classifi- 
cation of these proteids an effort has been made to perfect a ready method 
of quantitative separation for the purpose of obtaining such information as 
has been indicated, including a method for the determination of gluten. 
The matter did not prove as simple as it at first seemed, and it is hardly 
possible in this report of progress to go beyond a description of the pro- 
posed method of analysis, giving in connection therewith the more impor- 
tant analytical data which led to the selection of the method of analysis 
and, by way of illustration, the results of a few proximate analyses of the 
proteids of a few different wheats and flours. 

In as much as the following work is based almost entirely upon the 
characteristics of wheat proteids described by Osborne and Voorhees, and as 
a record of their work may not be readily accessible to all readers, the 
names and descriptions of these proteids as given by them in the Report of 
the Connecticut Agricultural Experiment Station for 1893, (p. 175, 185) 
are here repeated. With exceptions hereafter noted the presence in wheat 
and flour of proteids having the characteristics described by them have 
been frequently verified in the laboratory here, though no effort has been 
made to show their identity in composition. 

"I. Gliadin is the proteid which is readily dissolved from wheat flour and from 
gluten by hot dilute alcohol. * * * In absolute alcohol gliadin is entirely insoluble, 
but dissolves on adding water, the solubility increasing on adding water up to a certain 
point and then diminishing. 

"II. Glutenin. Characteristics of a proteid which can be dissolved only in dilute 
acids or alkalies are necessarily very few in number. * * * * It (is) probable that 
glutenin is slightly soluble in water and alcohol, especially if these are warmed. 

"III. Edeslin, a globulin belonging to the vegetable vitellins, soluble in saline 
•solutions, precipitated therefrom by dilution and also by saturation with magnesium sul- 
phate or ammonium sulphate, but not by saturation with sodium chloride. Partly pre- 
cipitated by boiling but not coagulated at temperatures below ioo . 

"IV, Leucosin, an albumin coagulating at52°; unlike animal albumin in being 
precipitated on saturating its solution with sodium chloride or magnesium sulphate. It 
is not precipitated on completely removing salts by dyalysis in distilled water. 

"V. A proteose, precipitated (after removing the globulin by dyalysis and the 
albumin by coagulation) by saturating the solution with sodium chloride, or by adding 
20 per cent of sodium chloride and acidifying with acetic acid. 

"VI. The solution filtered from the solution just described (V.) still contained a 
proteose-like-body which was not obtainable in a pure state. 

"The results obtained by us and described at length in our paper*, lead to the con- 
clusion that no ferment action is involved in the formation of gluten; that but two pro- 
teid substances are contained in the gluten, the gliadin and ihe glutenin, and that these 
exist in the wheat kernel in the same form as in the gluten, except that in the latter they 
are combined with water in an amount equal to about twice the weight of the water-free 
proteids." 

*Am. Chem. Jour., 15, 392, 471. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



83 



An examination of the characteristics of these proteids as described 
above, and more fully in the publication cited, led to the belief that all 
nongluten nitrogen will be dissolved from wheat meal by thoroughly ex- 
tracting with 10 per cent salt solution, and that the gluten nitrogen will 
remain undissolved. 

The first method attempted for the separation of these two classes of 
proteids was to place two grams of the material in a 500 c. c. Kjeldahl 
flask, mix thoroughly by shaking with a small quantity of 10 per cent salt 
solution, then adding the remainder of 100 c. c. of the liquid. The con- 
tents of the flask were shaken at intervals for three hours and then filtered 
on a 10 c. m. filter of good quality, washing four times with 25 c. c. of 
salt solution each time. The filter and contents were then carefully re- 
turned to the flask and the nitrogen in them determined by the usual 
Gunning modification of the Kjeldahl method. Duplicates agreed closely. 
The results were, however, unsatisfactory as appears from the following : 

Different strengths of salt solution were used on a sample of straight 
flour containing 1.82 per cent of total nitrogen, with results as indicated 
below. 

Per cent in sal solution 15 10 5 2^ 2 \]/ 2 1 ^ 

Per cent nitrogen • 1.56 1.50 1.43 1.33 1.30 1.29 1.29 1.30 

Similar results were obtained on another sample of flour. 

Comparison was made on a complete series of mill products by using 
a 10 per cent and a 1 per cent salt solution. The per cent nitrogen in 
each residue, based on the original 2 g. of substance is shown. 





Patent 
Flour. 


Straight 
Hour. 


Low 
Grade. 


Dust 
Room. 


Ship 
Stuff. 


Bran. 


Wheat. 


10% salt solution 

I % salt solution 


1.28 
I.07 


i-45 
1-25 


I.92 

I.77 


I.49 
1-43 


I.9I 
I.78 


I.63 
I.60 


1-34 




Difference 


.21 


.20 


•15 


.06 


•13 


•03 


•17 





A further trial was made in which each of another series of mill 
products was washed fifteen times with a 1 per cent salt solution. The 
comparison with the results from washing four times, using the same 
strength of salt solution is shown in the next table. Figures show per cent 
nitrogen in undissolved residue based on weight taken for analysis. 



84 



ARKANSAS AGRICULTURAL EXPERIMENT STATION. 





Patent 
Flour. 


Straight 
Hour. 


Low 
Grade. 


Dust 
Room. 


Ship 
Stuff 


Bran. 

1. 6l 
•94 


Wheat. 


Washed four tim p s 
Was; ed fifteen times.. 


.91 


1.28 
.98 


I.52 
1.19 


I.42 
.87 


I.56 
•94 


i-39 
•95 


Difference 


.24 


•3° 


•33 


•55 


.62 


.67 


•44 





The filtrate at the end of the fifteenth washing still showed the presence 
of proteids. This last trial seems to indicate that a considerable quantity 
of the gluten of flour is removed by continued washing and that the same 
will occur to a considerable extent in the mechanical washing out of crude 
gluten. The long time required for this washing may have brought about 
some change in the form of proteids such as would tend to make the insol- 
uble more soluble. Perfectly concordant though not so marked results 
were obtained by less protracted washing. 

The foregoing method of separating the gluten from the nongluten 
having been found subject to such serious objections, the following method, 
which it was believed would obviate the difficulty to a considerable extent, 
was substituted for it. 

Two grams of the material to be examined are put into a 200 c. c. 
graduated flask and after mixing thoroughly with a 10 per cent salt solution 
the flask is filled to the neck with the same liquid. The contents of each 
flask are then shaken at intervals of ten minutes for one hour. At the end 
of this time the flask is filled to the mark, the contents well mixed and the 
whole is allowed to remain quiet for two hours. At the end of this time 
the supernatent liquid in the flask is filtered through a dry filter into a dry 
flask. If the filtrate is not perfectly clear the first portion is refiltered 
through the same filter. When sufficient clear filtrate has been collected 
exactly 100 c. c, measured in a pipette, are run into a 500 c. c. Kjeldahl 
digestion flask of the usual pear shaped form with long neck. To this 
solution 20 c. c. of the usual sulphuric acid used for Kjeldahl work are 
added. The contents of the flask are brought to a gentle boil and when 
the water has been driven off and the acid has quit foaming, the sulphate 
of potash is added and the digestion completed. Results obtained by this 
method agree quite closely with those of the preceding method when using 
the same strengh ot salt solution and washing four times. 

The amount of nitrogen obtained in the above process is computed 
to per cent on one gram of substance. If our hypothesis be true that the 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 85 

salt soluble nitrogen compounds correspond to those not gluten, and those 
only, the difference between the per cent of nitrogen in the salt extract 
and the per cent of total nitrogen in the sample will give the per cent of 
nitrogen which is present in those proteids which together form gluten, 
and this per cent of nitrogen multiplied by 5.7 will give the theoretical 
amount of gluten in the material examined. 

Numerous estimates of gluten in different grades of flours and wheat 
meal have been made by the above described chemical method, and on 
corresponding samples by determining the amount of nitrogen in crude 
gluten washed out by the usual mechanical process. The mechanical 
washing out of the gluten has been done entirely by Mr. Moore with great 
care. The amount of gluten found by the above described chemical 
method is higher, and in the lower grades of flour much higher than by 
the usual mechanical method followed by a nitrogen determination. That 
is, by computing the true gluten from the nitrogen contents of the crude 
gluten obtained. The proportion of impurities in the crude gluten, 
especially that from low grade flours is also large, so that decidedly erro- 
neous results would be obtained by the mechanical method unless the 
crude gluten be submitted to analysis and the impurities determined. 
When considering the large amount of time and labor involved this is de- 
cidedly objectionable. Furthermore, the question still remains, does this 
give the true gluten in the sample examined? It will be shown later that 
the chemical method proposed above gives results which are decidedly too 
low, making the error for the gluten obtained by the mechanical method 
still greater than appeared from the above comparison. The cause of the 
error can be better explained and more readily understood after a con- 
sideration of the next topic. 

DETERMINATION OF THE GLIADIN. 

An attempt has been made to separate the gliadin of wheat by a 
quantitative method which can be readily applied to various samples. 
After some more or less unsatisfactory attempts the following* has been 
found a more or less ready means of this separation or at least a ready means 
by which all proteids soluble in hot 75 per cent alcohol can be extracted. 

One gram of the material to be examined is put into a 500 c. c. 
Kjeldahl digestion flask. 100 c. c. of 75 per cent alcohol, free from 

*Since the method here described has been in use, the second edition of Chemistry and Analysis of 
Wheat, Flour, etc., by William Jago, has been received. In it (p. 78Q) he describes a method for determin- 
ing proteids soluble in alcohol, which perhaps requires a little less labor than the one proposed in the text, 
but it is quite certain from comparisons made that results for gliadin obtained in that way will be much 
too low. 



86 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

nitrogen compounds, are added and after shaking thoroughly the flask is 
placed upright upon a suitable sized ring of an ordinary water bath. 1 The 
one used here contains holes for eight flasks. The water bath is heated so 
as to keep the temperature of the alcohol just below its boiling point. The 
contents of the flasks are shaken at intervals during the first hour. They 
are then allowed to remain quiet for one hour, after which the hot, clear 
liquid can be decanted onto a 10 c. m. filter of good quality. 25 c. c. of 
hot alcohol are then added to the residue and it is again placed upon the 
flask for ten minutes before filtering. This is repeated six times. It has 
been thought best in some instances to completely remove all alcohol from 
the flask after the last washing and the adding of the well drained filter. 
This may be readily done by placing the flask on or within the water bath 
and driving out the vapor by the assistance of a syringe bulb connected 
with a glass tube or by connecting the glass tube with an ordinary Rich- 
ards' air blast. The presence of the alcohol has sometimes given trouble 
during the subsequent digestion in removing a large part of the acid by 
volatilization of the resulting compound. 

After the alcohol has been removed the nitrogen is determined in the 
usual way, care being taken that all particles adhering to the neck of the flask 
are washed down by the acid and digested. It is necessary in this instance 
to determine the nitrogen in the filters used and deduct it from the 
results. The difference between the total nitrogen and the nitrogen thus 
obtained gives the per cent of nitrogen in the alcohol extract. This also 
includes amides as will be shown later. 

A more ready method of obtaining the nitrogen contents of the alco- 
hol extract is to collect the filtrate directly into a Kjeldahl flask. Place 
the flask on a sand bath and properly adjust it to a Leibig condenser. 
The greater part of the alcohol can thus be distilled off in a short time 
without fear of accident. The last portion of the liquid may be readily 
removed by placing the flask on a boiling water bath and inserting into 
the neck a glass tube connected with a filter pump or air blast. By using 
one of these for each of two flasks a single water jet is made to do 
double duty. The neck of the flask connected with the blast should be 
allowed to drop nearly to the horizontal. After evaporating to dryness the 
nitrogen is determined in the usual way. 

Osborne and Voorhees suggest, as already noted, that it is possible that 
glutenin is slightly soluble in hot water and alcohol. There is always a 
greater or less cloudiness to the liquid when the alcohol extract, obtained 
as described^above, becomes cold. Among mill products this increases 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 87 

gradually from the finest flours to the bran. Pure germ, when extracted 
with hot alcohol, gave an extract which was very clouded, though the 
amount of proteid in solution by no means equaled the amount of gliadin 
which has been found in an equal amount of cold, perfectly clear, alcohol 
solution. It is possible that a proteid having this characteristic may exist 
in the germ. The general characteristics of this portion of the grain 
differ so greatly from the remainder that it seems quite possible that the 
proteids of the two portions should differ. 

A sample of the pure handpicked germ when submitted to the 
methods for separation of proteids which have been described above gave 
the following results: The total proteids (NX5.7) were 37.55 percent. 
Those soluble in salt solution were 15.33 per cent and those soluble in 
hot 75 per cent alcohol were 2.85 per cent. Another sample of germ 
contained 36.02 per cent of total proteids. The ether extracts in the 
two samples were 13.85 and 14.38 per cent respectively. 

THE PROTEOSE. 

On comparing the use of a 10 per cent and the use of a 1 per cent 
salt in the methods described for the determination of the salt extract it was 
found that, as indicated by the first method, there was a notably larger 
extract by the 1 per cent than by the 10 per cent salt solution, and a much 
greater decrease was found when a 20 per cent solution of salt was used. 
Thus a sample of low grade flour gave the following results : One per 
cent salt extract contained .66 per cent nitrogen, 10 per cent salt extract 
contained .48 per cent nitrogen, 20 per cent salt extract contained .20 per 
cent nitrogen to each gram of material extracted. 

With the hope of finding the true cause of this feature of the ques- 
tion a considerable quantity of perfectly clear 1 per cent salt extract of 
wheat meal was obtained. To this a sufficient quantity of dry salt was 
added to make a 10 per cent solution. A considerable precipitate was 
produced and this was found to be largely soluble in 75 per cent alcohol 
in a clear solution of which proteids were readily detected. 

If the proteids, or a portion of them, which are soluble in salt solu- 
tion are insoluble in alcohol they should be precipitated by the addition of 
alcohol. When 50 c. c. of the clear, filtered 1 per cent salt extract were 
mixed with sufficient strong alcohol to make the resulting mixture contain 
about 75 per cent, a considerable white flocculent precipitate was produced, 
which soon settled, giving a supernatent clear liquid. This filtered 
rapidly and gave a perfectly clear filtrate. The rapidity of flocculation of 



OS ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

the precipitate was increased somewhat on heating. The concentrated 
filtrate gave strong biuret reaction. In like manner a marked biuret re- 
action for proteids was obtained by concentrating ioo c. c. of alcohol 
filtrate when the added alcohol was such as to make 90 per cent of alcohol 
in the mixture. 

In following out this line of investigation, a solution was made by 
mixing 100 grams of wheat meal with 500 c. c. of 1 per cent salt solution, 
shaking at intervals for one hour and filtering at the end of three hours. 
The proteids insoluble in 75 per cent alcohol were precipitated from 40 c. c. 
of this perfectly clear filtrate by adding alcohol to make a mixture of the 
desired strength. An aliquot portion of the resulting clear alcoholic fil- 
trate, corresponding to 20 c. c. of the original salt solution, was evapo- 
rated to dryness in a Kjeldahl flask and a determination made of the 
amount of nitrogen. Similar nitrogen determinations were made when a 
10 per cent, and later a 15 per cent salt solution was used for extracting 
like quantities of the same wheat. In this manner is found the number of 
milligrams of nitrogen in the nitrogen compounds soluble in alcohol from 
20 c. c. of the salt solutions of the various strengths. Determinations of 
the total nitrogen contents of each of these salt solutions was also made 
and computed to milligrams in each 20 c. c. of solution. The results of 
both of these series of determinations are shown below. 

Alcohol Soluble 
Total Nitrogen. Nitrogen, 

m. g. m. g. 

I per cent salt solution 19.48 9.7 

10 per cent salt solution 18.6 8.8 

15 per cent salt solution 16.2 7.6 

It was found later that a part of this alcohol soluble nitrogen is from 
amides, but the amount of amides in the wheat was by no means sufficient 
to account for the whole of the nitrogen thus obtained, and furthermore, 
abundant indications of proteids were found in each case by suitably con- 
centrating the alcoholic filtrate and applying the biuret test. 

A further comparison of the extracts made by 1 per cent and by 10 
per cent salt solutions was made as follows : Salt extracts were made in 
200 c. c. measuring flasks as already described, except that four grams of 
the material were used so that 50 c. c. of the extract would correspond to 
one gram of the sample. This quantity of extract was mixed with 250 
c. c. of strong alcohol and allowed to stand over night. Nitrogen was 
then determined in both the filtrates and the precipitates with the following 
results : 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 89 

Precipitated by Alcohol. Per Cent Nitrogen. 

I per cent salt solution 21 

10 per cent salt solution 23 

Soluble in Alcohol. 

I percent salt solution .42 

10 per cent salt solution 27 

A similar trial on a sample of ship stuff gave results as follows: 

Precipitated by Alcohol. Per Cent Nitrogen. 

1 per cent salt solution 31 

10 per cent salt solution 31 

It seems clear that the difference in amounts of nitrogen compounds 
removed from wheat by i per cent and by 10 per cent salt solutions is due 
to such as are soluble in 75 per cent alcohol. Filtering hot did not ma- 
terially affect the results. 

A strong alcoholic solution of wheat proteids was made by mixing 
the meal with cold 75 per cent alcohol. On pouring this clear extract 
into 1 per cent salt solution a precipitate was produced which, when 
filtered off, gave a perfectly clear filtrate. Proteid in considerable quantity 
was detected in this liquid by various reactions. Furthermore, the liquid 
was found to give the reactions characteristic of proteoses: Not coagu- 
lated by heat ; a precipitate with nitric acid which disappears on warm- 
ing; a like reaction with potassium ferrocyanide and acetic acid; precipi- 
tation by 20 per cent sodium chloride and acetic acid. Authorities* 
also state that proteoses are precipitated by alcohol. Either this proteid 
is somewhat soluble in alcohol or it is the result of the decomposition of 
a proteid which is soluble in that liquid brought about by mixing with 
the 1 per cent salt solution. If it be the latter, what is the explanation 
of the alcohol soluble portion of the salt extract ? When the a'cohol 
solution of this proteid is concentrated it also exhibits the properties 
of proteoses mentioned. When this alcohol solution of the salt extract 
is concentrated somewhat it exhibits the character of gliadin solutions in 
alcohol in that it is precipitated either by the addition of water or of 
strong alcohol. 

A sample of fresh gluten was treated with hot 75 per cent alcohol and 
10 c. c. of a resulting concentrated extract were poured into 90 c. c. of 
1 per cent salt solution and a precipitate formed. This on the following 
morning was filtered off and, by sprinkling a little pure, fine animal charcoal 
on the wet filter, a perfectly clear filtrate was obtained. This filtrate con- 
tained a proteid exhibiting the same proteose reactions mentioned above. 

*Chittenden, Digestive Proteolysis, p. 62; Hammarsten, Physiological Chemistry, p. 26. 



90 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

Some months previous a sample of gliadin had been prepared, at 
least nearly pure, by precipitating the concentrated 75 per cent alcohol 
solution with absolute alcohol, and washing well with alcohol and ether, 
after which it was dried in vacuum over sulphuric acid. A 75 per cent 
alcohol solution of this was prepared, which, when poured into a con- 
siderable quantity of 1 per cent salt extract gave the usual precipitate. A 
clear filtrate, obtained without the use of animal charcoal again exhibited 
the proteose reactions. 

On a succeeding page (p. 95) is given a series of results obtained on 
about twenty samples of different wheats and parts of wheat in which it is 
shown that when like amounts of wheat or its mill products are treated 
under the same conditions with equal amounts of 1 per cent salt solution, 
the amount of alcohol soluble proteid removed from the wheat in the 1 per 
cent salt solution is practically identical. Many results, which it is thought 
unnecessary to give, show that the same would have been true if 10 per 
cent salt solution had been used, except that the quantity thus extracted 
would have been less. There is a great variation in the amounts of the 
other nitrogen compounds contained in these various samples. The only 
reasonable explanation of these facts seems to be that an alcohol soluble 
proteid which is slightly soluble in 1 per cent and less in 10 per cent 
salt solution exists in considerable quantities in the wheat. 

It seems evident that this proteid is gliadin and it appears from the 
behavior described that gliadin is not changed when it is dissolved in salt 
solution but that it remains gliadin. With the exception of being readily 
soluble in 75 per cent alcohol and but slightly soluble in weak salt solutions, 
it possesses what have been set aside as the characteristic reactions of 
proteoses. Apparently it was this body which was found by Osborne and 
Voorhees in their salt extracts and was designated by them as a proteose 
and a proteose-like body under captions V. and VI. 

In its alcohol solution (75 per cent) gliadin has not been found to 
exhibit the reactions of proteoses with common salt. The addition of 
large quantities of salt in bulk to such a solution was found not to cloud 
it in the least either with or without acetic acid. When salt in solution is 
added a precipitate will be produced but in such cases it seems to be 
attributable, in part at least, to the dilution of the alcohol with water. 
It has been pointed out by the authors named above that gliadin is 
soluble in considerable quantities in pure water but is precipitated from 
such solution by the addition of a very small quantity of salt. The ex- 
periments recorded above show that the precipitation is not complete. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 91 

This solubility of gliadin in salt solutions accounts for the fact that 
when flour is treated directly with large quantities of salt solution no gluten 
is formed. It also has an important bearing upon the determination of 
gluten in wheat or flour by the usual mechanical method of washing away 
the starch and weighing the residue. 

Twelve grams of Porter's "standard" flour, from spring wheat, was 
made into a dough with 10 c. c. of i per cent salt solution and allowed to 
stand for one hour. It was then tied in a linen cloth and worked between 
the fingers in one liter of the same salt solution for one hour. It having 
been found impossible to obtain a clear filtrate from the solution direct it 
was heated nearly to the boiling point. One hundred and seventy-five c. 
c. of a nearly clear filtrate from this were evaporated to about 30 c. c. and 
enough strong alcohol added to make the mixture contain 75 per cent. 
Ten c. c. of perfectly clear filtrate from this showed much cloudiness on 
adding a few drops of a solution of phospho-wolframic acid which cloudiness 
precipitated on standing. The remainder of the alcoholic solution when 
concentrated gave in repeated trials distinct biuret reaction for proteids,* 
the same rose color being exhibited as when gliadin is treated. 

It has been already pointed out that the so-called true gluten ob- 
tained by mechanical washing away of the starch and computing the re- 
maining proteids from the nitrogen contents of the crude gluten obtained 
gives results which are much too low when compared with the sum of the 
gliadin and glutenin in the sample examined. The explanation is here 
apparent. An indefinite amount of gliadin is dissolved and washed away. 
In view of this fact the mechanical method of determining gluten in wheat 
and flour is even more unsatisfactory than has formerly been thought. 

EDESTIN AND LEUCOSIN. 

If a perfectly clear 1 per cent salt solution extract of wheat be heated 
slowly to about 50 c. a cloudiness will begin to appear and if the liquid be 
kept at about 60 for some time a considerable quantity of flocculent pre- 
cipitate separates out. If this be filtered off and to the perfectly clear 
filtrate alcohol be added a still further precipitate occurs, which is less 
than when alcohol is added to the unfiltered solution. According to the 
descriptions of edestin and leucosin given by Osborne and Voorhees this is 
what would be expected if these two proteids are in the alcohol precipitate 

*The delicacy of the biuret reaction for this proteid may be increased by using a very small quantity 
(2 c. c.) of the concentrated solution, an equal amount of the strongest caustic potash solution, and, after 
adding the few drops of copper sulphate, adding aiso about one cubic centimeter of strong alcohol. After 
shaking the mixture gently the color will be concentrated in the clear alcohol which rises to the top. 



92 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

of the silt extract. It is difficult to determine what strength of alco- 
hol will produce complete precipitation of these proteids. From a con- 
siderable number of trials, the details of which it seems unnecessary to 
give here, it is believed that a strength of 75 per cent alcohol produces at 
least nearly complete precipitation, but it does not appear safe to stop 
short of that strength. It is not safe to increase the strength to 90 per 
cent for fear of precipitating the gliadin. 

The readiness with which these proteids can be separated from the 
liquid in which they are precipitated, suggests that they might be collected 
in a Gooch crucible, washed, dried and weighed in bulk. The precipita- 
tion from so large a bulk of liquid would seem to leave them quite pure. 
At least part of the precipitate caused by alcohol will not be redissolved 
when the alcohol is decanted and an excess of 1 per cent salt solution 
added. This change in solubility may be accompanied by a slight change 
in composition. 

AMIDES. 

To ascertain concerning the solubility of amides in 75 per cent alcohol 
200 m. g. of asparagin (pure. E. Merck) were dissolved in 50 c. c. of 1 
per cent salt solution. This solution was mixed with the usual amount of 
strong alcohol used for precipitating proteids from a like quantity of 
solution. A slight precipitate occurred which seemed to become more crys- 
taline on boiling. The liquid was allowed to cool thoroughly before filter- 
ing. The filtrate was collected in a Kjeldahl flask and the alcohol removed 
by boiling and evaporation on a water bath. A considerable quantity of 
asparagin crystals remained. On determining the nitrogen in the usual 
manner, a quantity was found equal to that contained in 25.7 c. c. of -^ 
ammonium hydrate. This is much in excess of the total nitrogen ob- 
tained from any sample of wheat examined. Allantoin,* another amide of 
wheat, is also soluble in alcohol. The amides, then, may be assigned to 
the alcohol solution, whether from the salt solution or from the original 
sample. 

In attempting to make a complete separation of the proteids of wheat 
based upon the amount of nitrogen found, a determination and location of 
the amides present is important. To that end it is assumed that in the 
sound, mature wheat all nonproteid nitrogen exists in the form of amides. 

The "official method" for the determination of the albuminoid nitro- 
gen has been found deficient for wheat in this respect: It directs, "If the 

* Watts' Dictionary of Chemistry, Vol. i. 1893. 



CONCERNING WHEAT AND ITS .MILL PRODUCTS. 93 

substance examined consists of seed of any kind, add a few cubic centi- 
meters of a solution of (potash) alum just before adding the cupric hydrate 
and mix well by stirring." The following results with and without alum 
were obtained on a sample of wheat meal. 

Per Cent 

Albuminoid Nitrogen. 

Copper hydrate and o c. c. alum solution 1. 53 

Copper hydrate and 5 c. c. alum solution 1.37 

Copper hydrate and 10 c. c. alum solution 1.35 

Copper hydrate and 15 c. c. alum solution 1.35 

Copper hydrate and 20 c. c. alum solution 1. 32 

The depth of blue color in the filtrate increased directly with the 
amount of alum used. That with no alum was almost colorless and that 
with 20 c. c. of alum had a strong blue tint. When no alum was used 
the filtrate showed but slight turbidity with a solution of phospho-wolframic 
acid while the others showed abundant precipitates. 

As suggested by P. P. Deherain,* phospho-wolframic acid was tried 
as a precipitant for the proteids, conducting the remainder of the experi- 
ment as when copper hydrate is used. In a few instances results were 
obtained which are fairly concordant with those given by the copper 
hydrate method. Generally, however, in wheat meals and flours the 
liquid filters badly and it was found almost impossible to obtain a clear 
filtrate. In later work it was found that when a solution of phospho- 
wolframic acid is added to a salt extract made as has been described, a 
precipitate occurs, which, when left over night, gives a clear supernatent 
fluid which filters readily and leaves a perfectly clear filtrate. On collect- 
ing this (50 or 100 c. c. with a few cubic centimeters of washings) in a 
Kjeldahl flask and adding 20 c. c. of concentrated sulphuric acid the water 
can be readily boiled off, especially if the flask be protected from the 
naked flame with a thin sheet of asbestos. When the acid ceases to foam 
it is cooled slightly, sulphate of potash added and the nitrogen determina- 
tion completed in the usual way. After adding the sulphate the time re- 
quired for the digestion is but a few minutes. 

The readiness with which the water may be driven off and the di- 
gestion completed in this way makes it preferable to determine the nitro- 
gen in the filtrate when the albuminoid nitrogen is precipitated by copper 
hydrate as in the official method. The difference between the nitrogen 
found and the total nitrogen of the sample gives the amount of albuminoid 
nitrogen with equal accuracy, while the time of digestion is much shortened, 

*Traite de Chimie Agricole, p. 267. 



94 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

the danger of breakage is lessened and the necessity for making a correc- 
tion for the nitrogen in the filters is prevented. The only requirements 
are that the water and reagents shall be free from an appreciable quantity 
of ammonia or other nitrogen compounds, and this is equally essential in 
all Kjeldahl work. 

AMOUNT OF GLIADIN IN SALT EXTRACTS OF WHEATS AND FLOURS. 

The results of a separation of the nitrogen compounds in the i per 
cent extract of a considerable number of samples of wheat, flour, etc., are 
given below. The separation has been made by the above methods. 
Precipitation of edestin and leucosin in alcohol of 75-80 per cent strength ; 
determination of the amide or nonproteid nitrogen in the filtrate after 
precipitating with phospho-wolframic acid ; estimating the soluble gliadin 
nitrogen by difference. A systematic arrangement of details of procedure 
are given on a subsequent page. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



95 



TABLE SHOWING NITROGEN OF COMPOUNDS SOLUBLE IN ONE PER CENT 
SODIUM CHLORIDE SOLUTION. 

Figures show nitrogen in each compound in per cent of one gram of substance examined. 
ARKANSAS MILL PRODUCTS. 



Kind of Material. 



Patent Flour 

Straight Flour 

Low Grade Flour 

Ship Stuff 

Bran 

Sifted Dust (outer bran). 



porter's flours. 



c 


, 




sl 


« c 


c 

V 


£ o 


5 c 

£ U V 

r. a at 


•0 .- 


is 


v v a 


ife 


H 


W^ " 


< 


•41 


.11 


•03 


•43 


•13 


•03 


•54 


.21 


•°5 


•7i 


■31 


.10 


1. 00 


.48 


• 2 3 


•5° 


.16 


.20 



c o 
■3 - 

~Z 

o 



.27 
.27 
.28 

•30 
.29 
.14 



Souvenir (extra patent) 

0000 Boss Flour (patent) . 
Standard Flour (straight) 

Strong Bakers' Flour 

Red Dog (low grade) 



.46 
.46 

•5° 
.68 

•97 



.11 


•05 


.11 


•05 


•15 


.06 


•30 


.09 


•45 


.25 



■30 

•3° 
.29 
.29 

.27 



WINTER WHEATS. 



Red, Arkansas 

Red, Arkansas (harvest '94). 

Currell, Kansas 

Zimmerman, Kansas 

White Wheat, Canada 

Oregon White 



•72 


•3i 


•5 2 


.19 


•7i 


•3° 


.68 


.26 


•5° 


.22 


.49 


.20 



SPRING WHEATS. 



.12 
.IO 
.09 
.12 
.07 
.07 



.29 

•23 

.29 

•30 
.21 
.22 



Red Wheat, South Dakota 

Red Fife, North Dakota 

Red Fife, Minnesota 



.81 


•35 


.60 


•25 


.64 


.28 



• 17 
.09 

.II 



.29 
.26 
•25 



An examination of the table will show that when the sum of the ni- 
trogen of the amides and of the alcohol precipitate is subtracted from the 
total nitrogen of the salt solution the difference is practically a constant 
for sixteen different samples of wheat and mill products. The average for 
these sixteen samples is .28 per cent of nitrogen for one gram of material. 
This nitrogen is from the gliadin soluble in 1 per cent salt solution under the 



96 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

conditions of the experiment. Four results vary to a considerable extent 
from the average of the other sixteen. Of these, one is the sifted dust 
room contents which consists of the outermost portion of the bran. The 
nitrogen here obtained is .14 per cent. The nitrogen in the direct alcohol 
extract of this sample was .36 per cent. Of this, .20 per cent should be 
credited to amides. The difference, or .16 per cent, represents that from 
the total gliadin in the material, and shows why a greater amount was not 
extracted by the salt solution. That gliadin is contained in the alcohol 
extract from this sample was verified by suitable reactions. Two other 
samples showing an unusually low difference are white wheats, each of 
which contains a very low per cent of gliadin. The remaining irregular 
sample is an Arkansas red wheat of the harvest of 1894. These include 
all samples which have been examined in this way. The mean difference 
for all samples, excluding dust, is .27 percent. 

The foregoing results seem to justify the proposing of a method for 
the determination of the gluten in wheat and flour based upon the sub- 
traction of a constant factor from the nitrogen found in a 1 per cent salt 
solution, which otherwise represents the nongluten nitrogen contained in 
the material. One per cent salt solution is preferable to a 10 per cent 
solution, in that it is more satisfactory in certain points of manipulation. 
Based upon the work done, the provisional factor of .27 per cent is pro- 
posed. The results indicate that another might be more applicable to a 
certain class of wheat. The work done is not sufficient to give definite 
conclusions on that point. 

The results of the foregoing work may be summed up in the following : 

METHODS FOR QUANTITATIVE DETERMINATION OF WHEAT PROTEIDS. 

Total Nitrogen. The Gunning modification of the Kjeldahl method 
has been used throughout this work. More concordant results have been 
obtained with one gram of material than with two grams. 

Nongluten Nitrogen. Put five grams of the material to be examined 
into a 250 c. c. measuring flask. Add about 15 c. c. of a 1 per cent so- 
lution of sodium chloride and shake thoroughly. To the resulting homo- 
geneous mass add enough of the same solution to fill the flask nearly to 
the neck. Shake the contents of the flask at intervals of ten minutes 
during one hour. Fill to the mark with salt solution, mix thoroughly and 
let stand for two hours. Decant the liquid onto a 12^ c. m. dry filter of 
good quality, leaving the greater bulk of the solid material in the flask. 
The filtrate will be clouded, but if refiltered through the same filter into a 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 97 

clean flask it will generally be perfectly clear. Determine the nitrogen in 
50 c. c. of this extract, noting precautions on page 93. From the per cent 
of nitrogen thus obtained subtract .27 per cent as corresponding to the ni- 
trogen obtained from the gliadin soluble in 1 per cent salt solution un- 
der the conditions prescribed above. The remaining per cent of nitrogen 
is that corresponding to the nongluten nitrogen in the sample examined. 

Gluten Nitrogen. This is the difference between total nitrogen and the 
nongluten nitrogen as obtained above. The gluten nitrogen may also be 
found by subtracting the sum of the edestin, leucosin and amide nitrogen 
from the per cent of total nitrogen. 

Edestin and Leucosin Nitrogen. To 50 c. c. of the clear salt extract, 
obtained as described above, add, in a Kjeldahl digestion flask of 500 c. c. 
capacity, 250 c. c. of pure 94 per cent alcohol (188 per cent proof, 
redistilled). Mix thoroughly and allow to stand over night. Collect the 
precipitate on a filter (10 c. m.) of good quality, return to the flask and 
determine the nitrogen, making proper correction for the nitrogen in the 
filter. 

If desired, these two proteids may be separated by coagulating the 
leucosin at 60 c. and precipitating the edestin by adding alcohol to 50 
c. c. of the clear filtrate as before. The nitrogen in each precipitate may 
then be determined. 

Amide Nitrogen. Precipitate all proteids from 100 c. c. of the clear 
salt extract obtained as above by adding 10 c. c. of a 10 per cent solu- 
tion of phospho-wolframic acid, made by dissolving the pure soiid in 
distilled water. Allow to settle before filtering and determine the nitro- 
gen in the clear filtrate. (See page 93.) In case of bran, and per- 
haps immature or sprouted wheat, it may be necessary to add a somewhat 
larger quantity of the acid solution to produce complete precipitation of 
the proteids. In such cases the filtrate should be tested by the addition 
of a few cubic centimeters of the acid. 

Gliadin Nitrogen. Extract one gram of the material with hot 75 per 
cent alcohol as described on page 85. From the per cent of nitrogen 
dissolved by the alcohol subtract the per cent of amide nitrogen. The 
difference will be the gliadin nitrogen. 

Glutenin Nitrogen. The difference between the gluten nitrogen and 
the gliadin nitrogen gives the glutenin nitrogen. 

Proteids. The amount of the various proteids may be found by mul- 
tiplying the per cent of the corresponding nitrogen obtained by 5.7. 
This factor is deduced from the average nitrogen contents of the proteids 



98 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

of wheat as found in a large number of analyses made by Osborne and 
Voorhees. It undoubtedly approximates much nearer the truth than the 
factor 6.25. 

Wheat for the above work should be ground so that the endosperm 
shall pass through a sieve having circular holes of J4 millimeter in diameter. 
The bran of the grain, being in thin flakes will be sufficiently fine if made 
to pass through a sieve with circular holes one milimeter in diameter and 
the work of pulverizing will be greatly lessened. The resulting parts must 
be thoroughly mixed. The error due to the presence of the undissolved 
meal in the measuring flask used for the determination of the salt extract 
is so small that it may generally be neglected. If desired, the flask may 
be readily remarked for the work by adding to the usual weight of meal 
in the flask exactly 250 c. c. of the salt extract. In this case care must 
be taken to wet the meal thoroughly with not more than 25 c. c. of the 
liquid, after which the remainder of the meal may be added. 

SEPARATION OF THE PROTEIDS OF CERTAIN WHEATS AND FLOURS. 

Following the plan of separation outlined above a proximate analysis 
has been made of the nitrogen compounds of certain flours and other mill 
products and of a few samples of wheat grown in different sections of the 
country. They are given mainly to illustrate the variations in the relative 
amounts of the different proteids. That this variation may be more 
clearly seen, one of the tables shows the nitrogen of the proteids in per 
•cent of the total nitrogen of the sample. The extension of such anylitical 
■work to a large number of samples of wheats and flours of different 
•characters is necessary before definite conclusions can be drawn as to the 
relation which the different proteids have to those characteristics, and inas- 
much as it is a new field of labor, the outcome of such work cannot be 
do retold. 

It has been frequently stated that bran contains no gluten. In the 
analysis of the sample of bran shown in the table both gluten proteids are 
shown to be present in considerable quantity. A portion of this gliadin 
is from adhering endosperm. However, the pure sifted dust, which con- 
sists of the outermost portion of the grain, contains a small amount of 
gliadin. The explanation of the formation of gluten by Dr. Osborne in- 
dicates that the presence of the gluten proteids in bran and the nonforma- 
tion of gluten in the usual mechanical method of separation are perfectly 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 99 

consistent. The true explanation seems to be that the woody fiber of the 
bran prevents the uniting of the gluten particles into the gluten mass 
characteristic of flour and wheat meal. 

The variation of the nitrogen compounds among different mill 
products from the same mill are interesting. Among these the gradual in- 
crease of amides, of edestin and leucosin and of glutenin from the finest 
flour to the bran and the corresponding gradual decrease of gliadin are 
worthy of note. In the series of mill products of which the analyses of 
the ashes were made, all were from the same wheat. It is pretty certain 
that those in this series of analyses are not all from the same wheat, which 
accounts for certain minor variations. All were taken from the mill at the 
same time and were of recent grinding. 

As between the patent flours from winter and from spring wheat the 
equal amounts of gliadin and the great difference in the amounts of 
glutenin are suggestive. There may also be a hidden meaning in the 
very low proportion of gliadin found in the two samples of white wheat 
examined. A knowledge concerning this and other matters relating to 
this subject may give information which will be useful in the blending of 
wheats and flours to improve the quality of the latter. This is now prac- 
ticed to some extent by bakers and millers upon their knowledge of the 
general physical characters of the material and it is believed by many to 
be attended with good results. 



100 



ARKANSAS AGRICULTURAL EXPERIMENT STATION. 



TABLE SHOWING NITROGEN OF NITROGEN COMPOUNDS OF WHEAT IN PER CENT 
OF TOTAL NITROGEN PRESENT. 

ARKANSAS MILL PRODUCTS. 



Kind of Substance. 



Patent Flour 

Straight Flour 

Low Grade Flour 

Ship Stuff 

Bran 

Sifted Dust 



Z M 
3 O 



8.1 

8.6 
ii. 8 
17.2 
26.3 
26.5 



.2Z 
O 



O 



64.2 
S4-o 

5°-5 
46.2 

23-7 
11. 8 



2fr 
O 



27.7 
47-4 
37-7 
36.6 
50.0 
61.7 



££ 



,c c 
V> 3 an 



6.4 
7.0 

9-5 
13.0 
17.8 
11.8 



< 



1.7 

1.6 

2-3 

4.2 

8-5 
14.7 



porter's flours. 



Souvenir 

0000 Boss Flour 

Standard Flour 

Strong Bakers' Flour 
Red Dog 



7.8 

7-4 

9-3 

14.7 

26.3 



92.2 
92.6 
90.7 
85-3 
73-7 



5°-7 
51.8 
5i-3 
45-5 
27-5 



4i-5 
40.8 

39-4 
39-8 
46.2 



5-4 
5-i 
6.6 

"•3 
16.9 



2.4 

2-3 

2.7 

3-4 
9.4 



WINTER WHEATS. 



Red, Arkansas 

Red, Arkansas (1894) 

Currell, Kansas 

Zimmerman, Kansas ... 
White Wheat, Canada 
Oregon White Wheat.. 



17-3 
13.2 
16.7 
16.5 
20.6 
18.7 



82.7 
86.8 
83-3 
83-5 
79-4 
81.3 



48.4 
45-7 
43-2 
42.4 
34-o 
34-7 



34-3 
41. 1 
40.1 
41. 1 

45-4 
46.5 



12-5 

8-7 

11. 4 

"•3 
15.6 

13-9 



4.8 

4-5 
3-4 
5-2 
5.0 

4-9 



SPRING WHEATS. 



Red Wheat, South Dakota 

Red Fife, Minnesota 

Red Fife, North Dakota.... 



15-5 

18. 1 
17.4 



S4-5 
81.9 
82.6 



42.6 
37-9 
36 4 



42.0 
440 
46.8 



10.4 
13.0 
12.8 



5.0 
4.6 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 



101 



TABLE SHOWING PER CENTS OF PROTEIDS IN WHEATS AND FLOURS. 

ARKANSAS MILL PRODUCTS. 



Kind of Material. 



Patent Flour 

Straight Flour 

Low Grade Flour 

Ship Stuff 

Bran 

Sifted Dust 



ids. 






c 


a 


a 


B 


s 


•S £ 


a 


■a 


u 


S - 


3 


.2 


3 


u 





O 


O 


9.86 


9.06 


6-33 


2-73 


10.66 


9-75 


5-76 


3-99 


12.54 


11.06 


6-33 


4-73 


13-57 


11.23 


6.27 


4.96 


15-39 


"•34 


3.65 


7.69 


7-75 


5-7o 


.91 


4-79 



•63 

•74 
1.20 

1.77 

2.74 

.91 



porter's flours. 



Souvenir 

0000 Boss Flour 

Standard Flour , 

Strong Bakers' Flour 
Red Dog 



11.69 


10.77 


12.43 


11. 51 


12.86 


11.69 


15.16 


12.94 


15.16 


11.17 

1 



5-93 
6.44 
6.16 
6.90 
4.16 



WINTER WHEATS. 



Red Wheat, Arkansas 

Red Wheat, Arkansas (1894) 

Currell, Kansas 

Zimmerman, Kansas 

White Wheat, Canada 

Oregon White Wheat 



14.14 
12.48 

I5-05 

13-17 

8.04 

8.21 



4.84 

5-°7 
5.08 
6.04 
7.01 



11.69 


6.84 


4.85 


10.83 


5-70 


5-13 


12.54 


6.50 


6.04 


1 1. 00 


5-59 


5-41 


6.38 


2.74 


3- 6 4 


6.67 


2.85 


3.82 



.63 
•63 

.86 
1. 71 
2.57 



1.77 
1.08 
1. 71 
1.48 

i- 2 5 
1. 14 



SPRING WHEATS. 



Red Wheat, South Dakota 

Red Fife. Minnesota 

Red Fife, North Dakota 



19.15 


l6.I9 


8.I5 


12.31 


IO.O9 


4.67 


; II. 12 


9.18 


4-05 



8.04 

5-42 
S- l 3 



2.00 
1.60 
1-43 



ACKNOWLEDGMENTS. 

Thanks are due the following for samples of wheat and flour' for this 
work: The L. C. Porter Milling Company, Winona, Minn.; Prof. E. 
A. Burnett, Brookings, S. D. ; Prof. C. B. Waldron, Fargo, N. D. ; Mr. 
Robert Dawson, Paris, Ont. ; Prof. C. C. Georgeson, Manhattan, Kas. ; 
Prof. H. T. French, Corvalhs, Ore., and Mr. Andrew Boss, St. Anthony 



102 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

Park, Minn. Through the kindness of the late Fayetteville Milling Com- 
pany and of Mr. B. F. Johnson and his son, the data of the various test 
runs recorded in this bulletin and the various samples of mill products 
used for analysis, have been procured. 

The large amount of analytical and other routine labor which have 
resulted in that portion of the bulletin relating to the separation of the 
proteids of wheat, and the making of certain analyses recorded in Part L, 
have been greatly facilitated by the earnest cooperation of Mr. J. F. 
Moore, who has faithfully performed all duties assigned to him. 

G. L. Teller. 

Chemical Laboratory, Arkansas Experiment Station. 



CONCERNING WHEAT AND ITS MILL PRODUCTS. 103 

APPENDIX. 

Since the foregoing pages were sent to press an effort has been made 
to determine whether or not the proteose bodies found by Dr. Osborne 1 in 
the water or salt solution extracts of oats, rye and barley, and by Drs. 
Chittenden and Osborne 2 in similar extracts of maize, may be attributable 
to characteristics of the alcohol soluble proteids of those grains, such as 
have been pointed out as belonging to the gliadin of wheat. To that end 
extracts of each were made with 75 per cent alcohol and with a 1 per cent 
salt solution. 

Of each clear filtered salt solution extract 25 c. c. were mixed with 
125 c. c. of 94 per cent alcohol. The resulting precipitates were filtered 
off and the clear filtrates were each found to possess the following reac- 
tions in common with solutions prepared from wheat in like manner : A 
precipitate upon dilution either with water or with absolute alcohol. A 
precipitate or cloud with phospho-wolframic acid, which precipitate dis- 
solves on warming and reappears on cooling. Nitric acid does not pro- 
duce a precipitate in such dilute solutions. 

Of each alcohol extract 25 c. c. were mixed with 125 c. c. of 1 per 
cent salt solution. A clear filtrate from the resulting mixture gave in each 
case reactions for proteids. The resulting precipitates dissolved more or 
less completely on warming and reappeared on cooling. With nitric acid 
this solution from wheat gave a cloud which quickly disappeared on warm- 
ing. With the rye solution no change was seen* until the liquid was cooled 
with ice. A dense cloud then appeared while a similar tube of the liquid 
without the acid remained perfectly clear. The cloud disappeared on 
adding strong alcohol as well as on warming. In the solution from barley 
a similar but less marked cloud was obtained on cooling with ice. No pre- 
cipitate with nitric acid was obtained in these dilute solutions from either 
corn or oats. Certain other reagents gave, in each case, precipitates which 
dissolved on warming and reappeared on cooling. A nearly clear water 
solution obtained by mixing the 75 per cent alcohol extract of corn with a large 

1. Conn. Exp. Sta. Reports, 1890 and 1894. 

2. Amer. Chem. Jour. Vols. XIII and XIV. 



104 ARKANSAS AGRICULTURAL EXPERIMENT STATION. 

excess of water, gave a precipitate with nitric acid which did not dissolve, 
but increased on warming. When, however, a quantity of strong alcohol 
was added to the liquid the precipitate immediatelv dissolved. 

With each grain, including wheat, the clear alcohol extract of the meal 
gave precipitates in the cold with phospho-wolframic acid and with tannic 
acid, each being in solution in 75 per cent alcohol. In each instance the 
precipitate dissolved on warming and reappeared on cooling. A similar 
precipitate was given with nitric acid and the liquid became more or less 
yellow on boiling. As shown above, the compounds of these proteids with 
nitric acid are very soluble in dilute alcohol. With phospho-wolframic acid 
the cloud which at first dissolved reappeared when the liquid was kept 
near its boiling point for a short time. In the alcohol extract of corn the 
precipitate with tannic acid is slight, even with much reagent. It is very 
readily seen if the strong solution of proteid be diluted with an equal bulk 
of 75 per cent alcohol, sufficient reagent added and the whole cooled 
with ice. 

These facts, in connection with certain others pointed out on previous 
pages of this bulletin, support the belief that the proteose bodies which 
have been found in the water or dilute salt extracts of these various grains 
are really the alcohol soluble proteids, small quantities of which have been 
carried into solution and exhibit their characteristics unchanged. Further- 
more, these alcohol soluble proteids are seen to possess certain properties 
which have been thought to be characteristic of proteoses. 

• G. L. Teller. 

Fayetteville, Ark., October 3, 1896. 

3. Physiological Chemistry, Charles, (1884) p. 117. Physiological Chemistry, Ha'mmarsten, Mandel, 
(1893) p. 25. Dige.tive Proteolysis, Chittenden, (1894) p. 62. Watts' Dictionary of Chemistry, (1894) Vol. 
IV, p. 331. 



